[Predictive factors of hospital admission in ambulatory surgery at a regional hospital].

Background: Hospital admission following ambulatory surgery is a valid measure of morbidity and a quality indicator. To improve the efficiency of an ambulatory surgery unit it is essential to study the factors associated with unexpected hospital admission. Our goal was to analyze the association of age, ASA, type of surgical and anesthetic procedures, surgical duration, pain, vomiting and surgical and anesthetic complications with unexpected hospital admission.

Patients And Methods: Retrospective case-control study. The cases were all patients who underwent ambulatory surgery in the Viladecans Hospital (Barcelona, Spain) from October 1990 till May 1996 (n = 6,071), cases (n1 = 93), controls (n0 = 552). Logistic regression models with a predictive variable and multiple logistic regression were obtained. OR and 95% CI were calculated.

Results: Age was not significant for admission. ASA greater than status 1 (OR: 3.4 [1.4-9]); p = 0.01), the procto-perineo-sacrococcygeal procedures have significant risk (OR: 35 [4-304]; p < 0.00001), and other types of surgery were not significant. General, spinal anaesthesia and non-spinal locoregional ones with sedation were not significant (p > 0.2), but spinal anesthesia with deep sedation carried a significant risk (OR: 20 [3-122]; p < 0.00001). Surgical duration higher than 40 min (OR: 22 [5-94]; p < 0.00001), pain (OR: 12 [3-55]; p < 0.00001) and vomiting (OR: 8.5 [1.2-59]; p = 0.03) were significant factors in predicting hospital admission.

Conclusions: The factors related with unexpected hospital admission following ambulatory surgery were: surgical and anesthetic complications, pain, procto-perineal and sacrococcigeal procedures, spinal anesthesia with profound sedation and a surgical duration time higher than 40 min.